Archimedes was a hack.
He's fameous for saying: "Give me a place to stand on, and I can move the earth." Turns out no one would notice.
For a male adult to move the earth the fulcrum would need to be placed one kilometer from where it makes contact with the earth (at the south pole). The lever it's self would be six and a half billion light years long. Based on average male height, Archimedes would move his end approximately one point six meters (1.6m) which would translate to the earth being moved a distance less than the diameter of a proton. What he didn't specify is that he also needs an equally immovable fulcrum and a lever of unbreakable material that has absoloutely no flex aross it's six hundred billion lightyear length.
I would wager that I could get a better result bastardising Newtons third law by moving every person on earth to the same landmass and having them to all jump at once. While it would be a logistical nightmare, it's actually much more plausable than the fantastical notions of manufacturing an intergalactic sized phallic device of Archimedes.
Someone has actualy already figured out all the maths regarding this possibility. Lets see if I win my bet: Aproximatly 7 billion people with average weight of 50 kg (counting kids, midgets, hobbits etc); Jumping about one foot high. You get the result from the push off part of the jump rather than the landing (which makes sense if you stop to think about what's happening) and the Earth would move about a hundredth of the radius of a hydrogen atom.
The hydrogen atom is aproximately 100,000 times larger than the proton. That means that the jumping method moves the earth around 1000 times more than the intergalactic lever. So I win the bet!